public Task <ICollection> GetOrphansAsync(string entityName, IPersistentCollection collection, CancellationToken cancellationToken)
{
if (snapshot == null)
{
throw new AssertionFailure("no collection snapshot for orphan delete");
}
if (cancellationToken.IsCancellationRequested)
{
return(Task.FromCanceled <ICollection>(cancellationToken));
}
return(collection.GetOrphansAsync(snapshot, entityName, cancellationToken));
}